I'm a Sony user and installed the Lightroom 4 trial. It imported the old 3.6 catalog and gave me a nice new Lightroom 4 catalog. So far so good. Everything looked normal.

Now, when I import new .ARW (Sony Raw) pics into LR4, I'm not getting the lens information correctly. I use a tool call 'alphalensinfo' that reads .ARW files and creates .XMP files with the correct lens name. LR3.6 used to import the pics and read the XMP, giving a correct lens name in the LR catalog. LR4 seems to fail at this.

For instance, with my Samyang 8mm, Alphalensinfo would add the exif field to the XMP file saying "Samyang 8mm". LR3.6 then shows "Samyang 8mm" for the lens, after import. LR4 shows "---" for the lens.

I also repeated the test using the very latest version of exiftool (the revision history says they fixed a couple of bugs in handling the lens tags for sony images).

From some empirical evidence, it looks like if the lens was correctly identified by LR4, then you can rename it with exiftool.

However the samyang lens, which is tagged as "----" in LR4, cannot be fixed and no matter what you do, it always displays as "----" (and if you resave the xmp, it overwrites your valid lensid string with ----).

As an example, I have a tamron lens which was previously called "60 F2.0" and now is just "60 F2", and I was able to fix it.

I have seen that the xmp file for samyang images is slightly different, but I have not yet a solution.

Well, I tried again. In a similar way to Mycroft did above. I used alphalensinfo to make a .xmp file for my lens (I tried various results with identical results). I import the pic into LR4 and the lens name appearing in Lightroom is *NOT* what I had put into the XMP - it is some kind of Adobe default lens name. If I then 'save metadata to files' from light room, I can see LR4 has amended the XMP. If I use notepad to edit the aux:Lens field again to reflect what I want it to really say, save the xmp file then use LR4 to "read metadata from files", it ignores my new aux:Lens information. A re-save of the metadata updates the XMP file again back to that LR4 default lens name.

This is most annoying.

If I follow the exact same steps, in LR3.6, it all works properly and my aux:Lens fields in the XMP files are read correctly by lightroom.

You might add your 2-cents to the feedback thread linked near the beginning of this thread, along with doing a +1 to indicate you have the same problem. The feedback site is where to report issues, and the camera-raw engineer Eric Chan has already commented on that thread.

Like you, I am both a computer guy and a camera guy, and cannot quite determine from what people have said, none being official Adobe people, whether there is a way to use some plug-in or SQLite command to fix things or not. LR4 is obviously doing something different than LR3 but since the fix for previous versions of LR seems like a hack, then LR4 doing something different wouldn’t be a bug, but having a new hack would be useful. I would guess that a plug-in might need to be written to do this specific function if that Adobe_AdditionalMetadata.xmp data area needs to be modified.